1. Technical Field
The present invention relates to cognitive radio and, more particularly, to spectrum sensing methods, systems and devices.
2. Description of the Related Art
The congestion and over-use of unlicensed frequency bands in many countries throughout the world has led to the development of cognitive radio techniques that permit the detection and use of licensed frequency bands in a way that does not interfere with licensed transmissions. Cognitive radio techniques are based on the concept of spectrum under-utilization, in which certain licensed frequency bands are rarely utilized to its maximum potential by licensed users. Indeed, among licensed bandwidth users, there is very little usage on a very large range of spectrum in both time and space. Cognitive radio is therefore a promising solution that aims to introduce secondary, low priority usage of licensed spectrum resources while ensuring that primary usage by licensed users is not interfered with.